Display device and control method for display device

Abstract

According to one embodiment, a display device includes a display panel including pixels arranged in a matrix, a common electrode, a pixel electrode disposed for each of the pixels, and a liquid crystal layer containing a polymer and liquid crystal molecules, a light source, and a controller controlling a voltage between the common electrode and the pixel electrode, and controlling an operation of the light source. The controller applies a voltage corresponding to an image component to write the image component between the common electrode and the pixel electrode in order from the pixel located on an opposite side to the light source in a first period, and turns on the light source to display an image corresponding to the written image component on the display panel in the first period.

What is claimed is: 
     
       1. A display device comprising:
 a display panel comprising a plurality of pixels arranged in a matrix, a common electrode, a pixel electrode disposed for each of the pixels, and a liquid crystal layer containing a polymer and liquid crystal molecules; 
 a light source emitting light to the display panel; and 
 a controller controlling a voltage between the common electrode and the pixel electrode, and controlling an operation of the light source, wherein 
 the controller applies a voltage corresponding to an image component to write the image component between the common electrode and the pixel electrode in order from the pixel located on an opposite side to the light source in a first period, 
 the controller turns on the light source to display an image corresponding to the written image component on the display panel in the first period, 
 the controller applies a transparent voltage for erasing the image component written in the pixel between the common electrode and the pixel electrode in a second period before the controller applies the voltage corresponding to the image component between the common electrode and the pixel electrode, 
 the controller turns off the light source in the second period, 
 the controller maintains the light source on in a third period following the first period to display one image composed of the image components written in the pixels on the display panel when writing of the image component to the pixels is completed and the first period ends, 
 a frame period in which the one image is displayed includes the first to third periods, 
 the light source includes a first light-emitting element emitting light of a first color, and a second light-emitting element emitting light of a second color, 
 the frame period includes a first field period having the first to third periods corresponding to the first color, and a second field period having the first to third periods corresponding to the second color and following the first field period, 
 in the first period included in the first field period, the controller applies the voltage corresponding to the image component of the first color to write the image component of the first color to the pixels, and turns on the first light-emitting element when the image component of the first color starts to be written to the pixels in order from the pixel located on an opposite side to the light source, 
 in the first period included in the second field period, the controller applies the voltage corresponding to the image component of the second color to write the image component of the second color to the pixels, and turns on the second light-emitting element when the image component of the second color starts to be written to the pixels in order from the pixel located on the opposite side to the light source, and 
 the controller applies the transparent voltage to erase the image components of the first color written in the pixels before the controller writes the image component of the second color to the pixels in the first period of the second field period. 
 
     
     
       2. The display device of  claim 1 , wherein the transparent voltage is a common voltage. 
     
     
       3. The display device of  claim 1 , wherein the controller applies the transparent voltage between the common electrode and the pixel electrodes simultaneously to erase the image components written in the pixels simultaneously in the second period. 
     
     
       4. The display device of  claim 1 , wherein the frame period includes the first to third periods in order of first period, third period and second period. 
     
     
       5. The display device of  claim 1 , wherein the frame period includes the first to third periods in order of second period, first period and third period. 
     
     
       6. The display device of  claim 1 , wherein the second period is longer than a time during which the image component is written to one pixel of the pixels in the first period. 
     
     
       7. A control method for a display device comprising a display panel including a plurality of pixels arranged in a matrix, a common electrode, a pixel electrode disposed for each of the pixels, and a liquid crystal layer containing a polymer and liquid crystal molecules, a light source emitting light to the display panel, and a controller controlling a voltage between the common electrode and the pixel electrode and controlling an operation of the light source, the control method comprising:
 applying a voltage corresponding to an image component to write the image component between the common electrode and the pixel electrode in order from the pixel located on an opposite side to the light source in a first period; 
 turning on the light source to display an image corresponding to the written image component on the display panel in the first period; 
 applying a transparent voltage for erasing the image component written in the pixel between the common electrode and the pixel electrode in a second period before applying the voltage corresponding to the image component between the common voltage and the pixel electrode; 
 turning off the light source in the second period; and 
 maintaining the light source on in a third period following the first period to display one image composed of the image components written in the pixels when writing of the image component to the pixels is completed and the first period ends; wherein 
 a frame period in which the one image is displayed includes the first to third periods, 
 the light source includes a first light-emitting element emitting light of a first color, and a second light-emitting element emitting light of a second color, and 
 the frame period includes a first field period having the first to third periods corresponding to the first color, and a second field period having the first to third periods corresponding to the second color and following the first field period, 
 the control method for the display device, further comprising: 
 in the first period included in the first field period, applying the voltage corresponding to the image component of the first color to write the image component of the first color to the pixels, and turning on the first light-emitting element when the image component of the first color starts to be written to the pixels in order from the pixel located on an opposite side to the light source; 
 in the first period included in the second field period, applying the voltage corresponding to the image component of the second color to write the image component of the second color to the pixels, and turning on the second light-emitting element when the image component of the second color starts to be written to the pixels in order from the pixel located on the opposite side to the light source; and 
 applying the transparent voltage to erase the image components of the first color written in the pixels before writing the image component of the second color to the pixels in the first period of the second field period. 
 
     
     
       8. The control method for the display device of  claim 7 , wherein the transparent voltage is a common voltage. 
     
     
       9. The control method for the display device of  claim 7 , further comprising applying the transparent voltage between the common electrode and the pixel electrodes simultaneously to erase the image components written in the pixels simultaneously in the second period. 
     
     
       10. The display device of  claim 7 , wherein the frame period includes the first to third periods in order of first period, third period and second period. 
     
     
       11. The display device of  claim 7 , wherein the frame period includes the first to third periods in order of second period, first period and third period. 
     
     
       12. The control method for the display device of  claim 7 , wherein the second period is longer than a time during which the image component is written to one pixel of the pixels in the first period.